Question Is NB frequency the same as FCLK?

Jun 30, 2019
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So in my BIOS I set my FCLK clock to 1867, but in CPU-Z my NB clock is listed as 1599.6, same as my RAM speed. What does this mean? I'm trying to push my FCLK clock up higher than my ram to try to isolate the cause of the instability of my OC by pushing FCLK up above RAM, and then if that proves stable, doing the same with RAM speed.
 

extreme_noob

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Pushing FCLK above ram frequency is a terrible way to judge if the ram frequency would be stable. Whether FCLK is stable has nothing to do with whether ram frequency is. Generally how high FCLK can go depends on how good your CPU's memory controller is, which is mostly silicon lottery. It has nothing to do with how far ram can go, and usually tops out at about 1900Mhz on most chips, while some ram can actually go to 2500. Just put in the higher ram frequency settings straight away and if it doesn't post, it isn't stable.
 
Jun 30, 2019
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Im trying to test my cpu's binning by pushing up fclk not memory OC. Sorry if I was unclear in my first post. I know that my computer is unstable at 1867 FCLK 3773 RAM but im trying to find out what's causing it to. It does post at those frequencies just it dies in torture testing.
 

extreme_noob

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Im trying to test my cpu's binning by pushing up fclk not memory OC. Sorry if I was unclear in my first post. I know that my computer is unstable at 1867 FCLK 3773 RAM but im trying to find out what's causing it to.
It's probably not FCLK at that point. If it's unstable, try tweaking with voltages and timings. That's way more likely to cause instability than FCLK. And anyways for daily use, 3600Mhz with tighter timings is likely going to be better for any ryzen processor.
NB is UCLK, not FCLK anyways. UCLK is the memory controller frequency, and that is synced with the memory frequency.
 
Jun 30, 2019
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Also what are the chances of ram overheating causing a system crash in memtest86? I kinda want to push my ram to CAS 16 3733 at 1.45V to see if it could handle those speeds if voltage was high enough but if it crashed how would I know that it wasn't a temp problem?
 

extreme_noob

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Oh ok thanks. So to find out if that overclock may work I should leave FCLK at default and push my ram on up? And then if its stable bump FCLK up to match?
Increase FCLK so that it is equal to MCLK (memory clock). Always keep it the same. Don't make it different, unless you're really pushing >4.2GHz ram and your FCLK isn't stable at 2100Mhz or something.

Also what are the chances of ram overheating causing a system crash in memtest86? I kinda want to push my ram to CAS 16 3733 at 1.45V to see if it could handle those speeds if voltage was high enough but if it crashed how would I know that it wasn't a temp problem?
RAM doesn't usually overheat itself. Assuming good case airflow, ram sticks don't actually generate a lot of heat. It's the components around it, mostly CPU, but some GPU, which can "cook" the sticks. 1.45V should be safe for daily, but don't push it any higher or else it may degrade. Temps should be okay, but checking that is what stability testing is for. Test in memtest86 all 11 tests for 4 passes. It's very rare for memtest86 crashes to be temp related, but possible. Even after it passes all memtest86 it may not be stable, since that only stresses and therefore heats the ram. So use prime 95 to stress CPU as well (AFTER using memtest86). There's a specific setting set that I use for testing.
I use version 286 since that supports Ryzen well but still has the appropriate FFT sizes. First off, disable AVX. Do this by going into local.txt and typing in a new line "CpuSupportsAVX=0". AVX results in higher unrealistic temps. You want to enable it for CPU oc testing but it's not necessary for mem oc testing.
Then go into p95. Select blend, then select custom. Set min FFT size to 512K, and max to 4096K. Set memory to use to approximately 75% of what is available. I generally just set it to 10000MB on my system with 16GB ram. Set time to run each FFT to 15 minutes.
Run for 4-8 hours. If all threads are still working by then, you are stable, or at least as close to stable as you can get. Generally, if the memory fails here but not memtest86, it's a temp issue.

This is, of course, very tedious. So I suggest just using memtest86 alone for minor tweaks and then once you've decided on the settings you want to run daily, then do the full suite of testing described above.
 
Jun 30, 2019
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So I've got a stable overclock, but my CPU is sitting at 89C under load from Prime 95 and my ram RAM is at about 40C. Is this safe? The maximum operating temp for the 3600 is 95C so I'm below that but that still seems pretty high.
 

extreme_noob

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So I've got a stable overclock, but my CPU is sitting at 89C under load from Prime 95 and my ram RAM is at about 40C. Is this safe? The maximum operating temp for the 3600 is 95C so I'm below that but that still seems pretty high.
It is high, and preferably temps would be lower, but it probably won't cause any short term damage. In the long run, it may degrade the chip faster, but it will likely still last more than 5 years. Are you running a CPU OC?
The RAM temp itself should be fine but you'll want to make sure it stays stable.
If you want to lower temps of both, I suggest setting case fans to a more aggressive fan curve, or dial back the CPU OC, if you have OC'd it, since that can contribute to RAM temps as well.
You'll also want to play a game or do a graphics intensive benchmark like unigine superposition or 3DMark Timespy, just to make sure heat from the GPU isn't cooking the RAM.
 

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